MALIBU, Calif. (KABC) -- A map provided by the Los Angeles County Fire Department on Tuesday morning showed the updated perimeter of the massive Franklin Fire and its evacuation areas in and around Malibu.

Thousands of residents were under evacuation orders as firefighters battled the wind-driven wildfire that burned near seaside mansions and Pepperdine University, where students sheltering at the school's library watched as the blaze intensified and the sky turned deep red.

It was not immediately known how the so-called Franklin Fire started, but fire officials estimated that nearly 3 square miles of trees and dry brush had burned and structures were threatened.